The Pacific Northwest watershed (HUC-2 region 17) drains the Pacific Northwest including the Columbia, Snake, and Fraser Rivers, one of the most hydropower-rich regions in the US. Covering 322,981 sq mi across 9 states and provinces, it is one of the 18 major drainage regions of the contiguous United States.
Use the interactive Pacific Northwest watershed map below to explore all 12 HUC-4 sub-regions within the basin. Click any sub-region for its code, name, and area. Or view the interactive US watershed map to see all 18 major basins side by side.
Major Drainage Basins
Pacific Northwest Watershed by the Numbers
- HUC-2 code: 17
- Total area: 322,981 sq mi
- States and provinces: CA, CN, ID, MT, NV, OR, UT, WA, WY
- HUC-4 sub-regions: 12
HUC-4 Sub-regions of the Pacific Northwest Watershed
The USGS Watershed Boundary Dataset divides the Pacific Northwest region into 12 HUC-4 sub-regions. Each sub-region drains into a distinct river system or coastal outlet within the larger basin:
| HUC-4 Code | Sub-region Name | Area (sq mi) |
|---|---|---|
| 1701 | Kootenai-Pend Oreille-Spokane | 52,029 |
| 1702 | Upper Columbia | 46,238 |
| 1703 | Yakima | 6,150 |
| 1704 | Upper Snake | 35,873 |
| 1705 | Middle Snake | 36,987 |
| 1706 | Lower Snake | 35,044 |
| 1707 | Middle Columbia | 29,904 |
| 1708 | Lower Columbia | 6,227 |
| 1709 | Willamette | 11,463 |
| 1710 | Oregon-Washington Coastal | 25,190 |
| 1711 | Puget Sound | 20,447 |
| 1712 | Oregon Closed Basins | 17,430 |
States and Provinces in the Pacific Northwest Watershed
The Pacific Northwest watershed spans 9 states and provinces: CA, CN, ID, MT, NV, OR, UT, WA, WY. Water falling anywhere within these boundaries ultimately drains through the Pacific Northwest basin’s river network.
Frequently Asked Questions
What is the Pacific Northwest watershed?
The Pacific Northwest watershed is HUC-2 region 17 of the US Watershed Boundary Dataset. It drains the Pacific Northwest including the Columbia, Snake, and Fraser Rivers, one of the most hydropower-rich regions in the US, covering 322,981 sq mi across CA, CN, ID, MT, NV, OR, UT, WA, WY.
How large is the Pacific Northwest watershed?
The Pacific Northwest watershed covers 322,981 square miles, making it one of the 18 major drainage regions of the contiguous United States.
How many sub-regions does the Pacific Northwest watershed have?
The Pacific Northwest watershed contains 12 HUC-4 sub-regions as defined by the USGS Watershed Boundary Dataset.
→ View all 18 major US watershed basins on the national interactive map
